This invention relates to the steam-driven injection of water into a vessel and more particularly relates to the cooling of water subject to multiple-stage steam-driven injection into the pressure vessel of a nuclear system.
Pressure vessels in nuclear reactors may operate at pressures in excess of 1,000 psi in the course of generating steam for power production. It is desirable to employ the steam generated within the pressure vessel to insure the presence of an ample supply of cooling water in the core of the nuclear system.
Presently, as for example shown in U.S. Pat. No. 3,431,168 (which relates to an invention by J. E. Kjemtrup, was issued on Mar. 4, 1969, and is expressly referred to and incorporated herein, a sufficient water level within the pressure vessel is insured by employing a turbine-driven pump which is an expensive and complex assembly of components including a steam-driven turbine rotating a shaft for driving the pump. In other arrangements, the pump is driven by an electric motor which requires substantial active controls and depends upon electrically operated speed governing equipment for operation. The pump is accordingly subject to failure during a loss of electric power.
In the past, and as shown in U.S. Pat. No. 722,696, issued to W. W. Green on Mar. 17, 1903, a form of multiple-stage steam-driven injection of water into vessels has been accomplished.
However, in such kinds of steam-driven water injection, irrespective of whether the stages are arranged in series or parallel or combinations thereof, the output of each stage produces heated water, which reduces the efficiency of subsequent stages.